Balanced slide-valve



(No Model.) 4 Sheets-Sheet '1.

BALANGED SLIDE VALVE.

' No. 389,737. Petented Sept. 18,1888.

WITNESSES IN T e7 '80 MM.

(No Model.) 4 Sheets-Sheet 2.

G. W. CISCO.

A BALANCED SLIDE VALVE. "No; 389,737. Patented Sept. 1,8,1888.

WITNES- N. PETERS. Pvwm-Limu nphar, Walhinglnn, 0.42.

(No Model.) 4 Sheets- Sheet 3.

G. W. 01800.- V BALANCED SLIDBVALVE. 188889.787] 8 Patented Sept. 18,1888.

(No Model.) 4 sheets sh'et 4.

G. W.. 01800. BALANCED SLIDE VALVE. No. 889,737. l Patented Sept. 1.8,1888.

, WITNESSES UNITED STATES PATENT OFFICE.

GEORGE WASHINGTON OISGO, OF MONTVALE, NEW JERSEY.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 389,737, dated.September 18, 1888.

Application filed April 2, 1888. Serial No. 260,288.

employed on railway-locomotives.

The object is to produce a slide-valve which shall be so constructedthat the friction and consequent wear of the parts while working will begreatly reduced, if not entirely over-v come; furthermore, to produceaslide valve in which steam leakage will be obviated, thus renderingfrequent packing of the stuffingboxes unnecessary; furthermore, toproduce a slide-valve in which but a very small proportion of thesteam-power will'be lost from condensation of the steam; and, finally,to produce a slide valve which shall be simple of construction,eflicient and durable in use, and comparatively inexpensiveofproduction.

Heretofore slide-valves as constructed have been defective in that thesteam, entering from the top of the chest, presses on the valve andtends to grindit upon its seat, and thus create a large amount offriction, also in rushing from one port to another to lift the valvefrom its seat, causing it to press the Valverstem against thestuffingboX, resulting in uneven wear. Furthermore, the large amount ofspace in the steam chest tends to facilitate the rapid condensation ofsteam, a very troublesome feature and one that is a source of constantannoyance to engineers. I

It' is the object of the present invention to overcome the objections bydoing away with all of thespace in the steam-chest not actually employedby the valve and in constructing a steam-chest in which only the amountof steam requisite to drive the engine will be admitted; furthermore, tosupply means for the escape of the condensed steam at all times withoutthe necessity of the engineer having to attend to it,

(No model.)

With these objects in view the invention con sists in the combination,with the cylinder,ofa valve-chest seated thereon,and having suitableopenings formed in the bottom to allow the steam to enter the cylinder,and an opening for the escape of the exhaust-steam; furthermore, in thecombination,with the said valve-chest,of a sliding valve designed to fitwithin and move upon the bottom of the valve-chest,and having openingscorresponding to those in the valveseat,whereby upon each stroke of thepiston the valve will be made to open and close the parts alternately,and thus supply the steam to the cylinder at proper intervals;furthermore, in the combination, with the said valve-chest, of a bonnetor plate secured thereto and designed to hold the slide-valve inposition within the said chest; furthermore, in the combination, withthe slide-valve, of a valve-stem connected therewith and extending toand connecting with the crank-levers operated by the piston, whereby thesaid valve may be made to perform the function for which it is designed;and, fiually,in the various novel details of construction whereby itsobjects are attained.

In the accompanying drawings, forming part of this specification, likeletters of reference indicate corresponding parts wherever they occur.

Figure l is a perspective view of the valvechest with the top and oneside removed,showing the arrangement of the ports. Fig. 2 is aperspective view of the slide-valve, also showing the arrangement of theports. Fig. 3 is a vertical sectional view of the valve, showing theopenings for the bolts used in securing the valve-stem in position. viewof the same, showing the grooves for supplying oil to the valve-seat.Fig. 5 is a top 'plan view of the bonnet or plate for holding the valvein place. Fig. 6 is a side elevation of one of the sides of thevalve'chest. Fig. 7 is a side elevation of the valve-stem. Figs. 8, 9,10, 11, and 12 are detail views of various parts of the apparatus, whichwill be described as they occur in the specification. Fig. 13 is a sideelevation showing the apparatus put together. Fig. 14 is a sectionaldetail view of the end of the head of the valve-stem, and Fig. 15 is avertical sectional view of the device with theparts assembled.

Fig. 4 is a top plan

